In the prior art, touch screen monitors are commonly used to assist users with selecting items displayed on a monitor. Selecting items is commonly performed using a pointing object, such as a stylus or a finger. Such touch screen monitors often employ a capacitance sensor to identify the location at which the pointing object touches the display monitor. The identified location is then compared to the location of images displayed on the monitor in order to determine what the user is identifying.
Although these prior art touch screen monitors have become reliable and inexpensive, the prior art devices do not incorporate any built-in sensing elements suitable for measuring a touch event reliably, and although many of these prior art devices are fine for dry and clean environments, they often fail in dirty, wet or adverse conditions.